Cinestar 8 at 14,000 Feet

Discussion in 'Cinestar 8' started by Wayne Mann, May 3, 2014.

  1. Wayne Mann

    Wayne Mann Member

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    Hi Guys,

    I have a job next week and I have been asked if I can fly my rig at 14,000 feet. Honestly, I am more worried about being able to breathe than whether or not my machine will fly at that altitude.:) My Cinestar 8 has a Gh4 on it flying with APC 14x5.5 MRP props. It has a really good amount of reserve lift at the end of the batteries so the setup works really well. For flying Epics I switch out to the APC 16x5.5 MRP. I just have a sinking feeling that the 16x5.5 props won't be near enough extra lift for 14,000'. APC has 18' MRP now, but I can't get them in time. Anyone have any suggestions?

    Thanks


    Wayne Mann
     
  2. Gary McCready

    Gary McCready Active Member

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    I as curious so I looked it up.
    Looks like air density is about .82 vs 1.2 for sea level. So looks like about 1/3 less lift.
    Not really sure how it will effect things, but it is a very dramatic difference. Not even
    thinking about oxygen levels being 1/3 less.
    Sorry, I can't really offer suggestions. I live at sea level, that attitude would kill me.
    Height Temperature Pressure Density
    (m) (C) (hPa) (kg/m3)
    0000 15.0 1013 1.2
    4000 -11.0 620 0.82
    http://usatoday30.usatoday.com/weather/wstdatmo.htm
     
  3. Gary Haynes

    Gary Haynes Administrator
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    Wayne you should be fine. I've flown at about 11,000 feet here in the Rockies. Others have posted on this same topic on the forum and found no ill effects. Only caveat is if you find that your hover throttle is much above the 50% where you currently fly your safety margin will be diminished. Example if your current load out has the throttle at 75% then you might have issues.
     
  4. Wayne Mann

    Wayne Mann Member

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    Thanks for the replies guys. I have flown my F3C contest helicopters that were set up for Florida conditions at 8000' and it was amazing at how little control power I had. Lift wasn't too much different in the way that it felt, but full cyclic rolls and loops were interesting.

    I am running about 45% throttle in a hover with the 14x5.5 props so I have a lot of reserve lift at the end of a battery run. All I can do it try it with the 16" props.

    Thanks again.


    Wayne Mann
     
  5. Gary Haynes

    Gary Haynes Administrator
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    Give it a try with your standard props. If you don't like what you have then change props. Might save you some time.
     
  6. Cedar Beauregard

    Cedar Beauregard New Member

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    I would bring a set of xoar 15x6's.. You don't need more diameter as much as a steeper pitch if nothing else to slow the rpm in the thin air.. I've flown at 13,000 and liked the extra...
     
    Gary McCready likes this.

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